Conservative Investors Sleep Well provides as much ground-level insight
into investing as The
Intelligent Investor. 
Fisher implicitly agrees with the following tenets of Graham:
- The market is irrational in the short run.
 - But in the long run, value will be recognized by the market. 
 
Graham finds value by numerical valuation (sometimes stocks sell on the market
for less than working capital; when the market is that silly, buy.).  Fisher
wants good firms at a good price, so he provides an introduction to ranking
firms based on their business abilities.  Fisher's margin of safety lies in
finding competitive, well-run companies in good 
industries.
A
conservative investment then, is the investment in the well-managed, peer-beating
company with long-term prospects for growth or monopoly, whose prospects are
currently not valued properly by the ever fickle market.